For long-tail settings,
some works have considered means of
improving embeddings for tail classes.
For example, in [1]}, it was proposed to minimise
\( \Omega _{\rm range}( x ) \stackrel{.}{=}\max _{y \ne y^{\prime }} [ \gamma - \Vert  \mu _{y} - \mu _{y^{\prime }} \Vert _2^2 ]_+, \) 
